Powerful Category 3 Irene enters the Bahamas

By: Dr. Jeff Masters , 3:49 PM GMT on August 24, 2011

Share this Blog
20
+

Powerful Category 3 Hurricane Irene stormed through the Turks and Caicos Islands overnight, bringing hurricane-force winds, torrential rains, and storm surge flooding. On Providenciales in the Turks and Caicos Islands, where half of the population of these islands live, winds reached a sustained 65 mph at a personal weather station at Pine Cay, and the pressure bottomed out at 989 mb. The eyewall of Irene missed the island, with the center of the storm passing about 60 miles to the southwest. The center of Irene passed about 60 miles to the northwest of Grand Inagua Island, and Category 1 hurricane conditions were probably experienced on that island. Damage in the Turks and Caicos is likely to be much less than the $50 - $200 million wrought by Category 4 Hurricane Ike of 2008, since Irene's eyewall missed populated islands.


Figure 1. Morning satellite image of Irene.

Monday, Irene hit Puerto Rico as a tropical storm with 70 mph winds, but reached hurricane strength as it emerged into the Atlantic northwest of the capital of San Juan. One drowning death is being reported from the island, and the storm dumped up to 20 inches of rain in some areas. About 11% of the island was still without power this morning, and numerous roads were closed due to flooding and landslides. Irene did an estimated $17 million in damage to agriculture and $2 million to ports in Puerto Rico. Satellite estimates suggest that Irene has brought only 1 - 2 inches of rain to Haiti. With Irene now pulling away from Hispaniola, Haiti can expect only another 1 - 2 inches from the hurricane, and appears to have dodged a major bullet. Heavy rains of 3 - 6 inches were common across the Dominican Republic, where moderate flooding but no deaths occurred.


Track forecast for Irene
Continuing dropsonde missions by the NOAA jet have helped to significantly narrow the uncertainty in the 1 - 3 day forecasts from the computer models. Irene will track through the central Bahamas today, the northwestern Bahamas on Thursday, and approach the Outer Banks of North Carolina on Friday. However, the models still diverge considerably on their 4 - 5 days forecasts, and we don't know if Irene will plow up the mid-Atlantic coast into New Jersey, as the GFDL model is predicting, hit New England between Long Island, NY and Massachusetts, as the ECMWF, GFS, and HWRF models are predicting, or miss the U.S. and hit Canada, as the NOGAPS model is predicting.

Intensity forecast for Irene
Latest data from the Hurricane Hunters shows that Irene has paused in its intensification cycle. A gap has opened in the eyewall, and the central pressure has remained constant at 956 - 957 mb over the past few hours. However, the hurricane is embedded in a large envelope of moisture, and wind shear is expected to remain low to moderate, 5 - 20 knots, for the next three days. With water temperatures very warm, 28 - 30°C, these conditions should allow for intensification to a Category 4 storm sometime in the next two days. Satellite loops show that Irene is well-organized, with excellent upper-level outflow, and impressive spiral banding.

Irene's impact on the Bahama Islands
Irene is making a direct hit on Crooked Island (population 350) in the Bahamas, and will continue west-northwest and hit Rum Cay (population 80) and Cat Island (population 1700) late tonight. These unfortunate islands will bear the full brunt of Irene's 115+ mph winds and 8 - 13 foot storm surge, and suffer major damage that will take months to recover from. Major damage is also likely on Long Island (population 3000) and San Salvador Island (population 1000.) Shortly after midnight tonight, winds at the capital of Nassau, home to 70% of the population of the Bahamas, will rise above tropical storm force, and increase through the night. By late morning on Thursday, sustained winds will peak on Nassau at just below hurricane force, 60 - 70 mph. Nassau will miss the brunt of the storm, and I expect the airport should be able to re-open on Friday. Winds on Grand Bahama Island in Freeport will rise above tropical storm force late Thursday morning, and increase to a peak of 45 - 60 mph late Thursday afternoon. Grand Bahama will also miss the brunt of the storm, but Abaco Island to its east will likely experience Category 2 hurricane conditions Thursday afternoon. However, Abaco will probably miss the right front eyewall of Irene with the strongest winds and highest storm surge.


Figure 2. Wind distibution around Irene as of 1330 UTC (9:30am EDT) August 24, 2011. Irene was a Category 3 hurricane with 115 mph winds at the time. Hurricane force winds (yellow colors) extended over Crooked Island to the storm's northwest, and over Mayaguana Island to the east. Image credit: NOAA/AOML. Irene is a large storm, and its potential storm surge damage rated 3.9 on a scale of 0 to 6, with its wind damage potential rated at 2.5 on a scale of 0 to 6.

Irene's impact on the Southeast U.S.
Long-period ocean swells from Irene will reach the coast from Florida to North Carolina tonight, and continue to build as the storm approaches. The outermost rainbands of the hurricane will reach South Florida by Thursday morning, and spread over much of the eastern coastal portion of Florida during the day Thursday. If Irene follows the official NHC forecast through the Bahama Islands, the storm's expected radius of tropical storm-force winds of 130 - 170 miles will keep tropical storm conditions just off the east coast of Florida. Sustained winds of 20 - 30 mph can be expected along the coast of Florida during Irene's point of closest approach, and rainfall amounts of 1 - 2" will be common along the coast. Georgia, which could use the rain, will get very little. It is unlikely any airport in Florida or Georgia will need to close for Irene.

Late Friday night or early Saturday morning, Irene's outer spiral bands will move over the southern coast of North Carolina and the northeastern portion of South Carolina, and tropical storm-force winds of 39+ mph will arrive. Winds will steadily increase to hurricane force on the Outer Banks by Saturday night. The main damage from Irene in North Carolina will come from the storm's flooding rains of 4 - 12" that will fall in coastal areas. Fortunately, this region is under moderate to severe drought, so the damage will not be as severe as that experienced during Hurricane Floyd of 1999. Significant wind damage can be expected in the Outer Banks of North Carolina, and considerable storm surge damage may occur along the shores of Pamlico and Albemarle Sounds. If Irene's eye misses making landfall in North Carolina, total damage from the storm should be less than $200 million, and could be considerably less than that.


Figure 3. Sea surface temperatures for August 24, 2011. Temperatures of 26°C (79°F) are typically needed for a hurricane to maintain its strength (black line). This boundary lies just off the southern coast of New Jersey this year, which is much farther north than usual.


Figure 4. Predicted 5-day rainfall for the period ending Monday morning, August 29, at 8am EDT. Image credit: NOAA/HPC.

Irene's impact on the mid-Atlantic and New England
The impact of Irene on the mid-Atlantic and New England is highly uncertain at this point, because we don't know if the core of the storm will miss the coast or not. In general, the heaviest rains will fall along a 100-mile swath just to the west of where the center tracks, and the worst wind and storm surge damage will occur to the east. If the core of Irene stays offshore, the mid-Atlantic and New England may escape with a few hundred million dollars in damage from flooding due to heavy rains and storm surge. If Irene hits Long Island or Southeast Massachusetts, the storm has the potential to be a $10 billion disaster. Irene is one of those rare storms that has the potential to make landfall in New England as a Category 2 or stronger hurricane. It is difficult for a major Category 3 or stronger hurricane crossing north of North Carolina to maintain that intensity, because wind shear rapidly increases and ocean temperatures plunge below the 26°C (79°F) level that can support a hurricane. We do expect wind shear to rapidly increase to a high 30 - 50 knots once Irene pushes north of Delaware, which should knock the storm down by at least 15 - 30 mph before it reaches New England. However, this year sea surface temperatures 1 - 3°F warmer than average extend along the East Coast from North Carolina to New York. Waters of at least 26°C extend all the way to Southern New Jersey, which will make it easier for Irene to maintain its strength much farther to the north than a hurricane usually can. During the month of July, ocean temperature off the mid-Atlantic coast (35°N - 40°N, 75°W - 70°W) averaged 2.6°F (1.45°C) above average, the second highest July ocean temperatures since record keeping began over a century ago (the record was 3.8°F above average, set in 2010.) These warm ocean temperatures will also make Irene a much wetter hurricane than is typical, since much more water vapor can evaporate into the air from record-warm ocean surfaces. The latest precipitation forecast from NOAA's Hydrological prediction center shows that Irene could dump over 8 inches of rain over coastal New England.


Figure 5. Soil moisture profiles from yesterday show that a region of very moist soils ranking in the top 1% in recorded history (dark green colors) lie over northern New Jersey, Southeast New York, and Northeast Pennsylvania. Image credit: NOAA/CPC.

Tropical storm-force winds and heavy rains will move into Eastern Virginia Saturday afternoon, and push northwards to Delaware and coastal Maryland by late Saturday night. Tropical moisture through a deep layer of the atmosphere will also stream well ahead of Irene into New England on Saturday afternoon and evening, bringing what is called a "Predecessor Rain Event" (PRE). The Washington D.C., Baltimore, and Philadelphia airports will be right at the edge of the heavy rain and high wind area, and it currently appears they will not have to close for an extended period. The Philadelphia and New York City airports may not be as lucky, and it is possible they will suffer extended closures Sunday morning and afternoon. By late Sunday night, Irene's rains will move north of New York City, allowing the airports to re-open. The highest potential for damaging fresh-water flooding is in northern New Jersey, Southeast New York, and Northeast Pennsylvania, where soil moisture is near record high levels, and there is nowhere for the rain to go (Figure 5.) Heavy rains of 4 - 12" are likely across all of coastal New England if Irene passes within 100 miles of shore.

Links
For those of you wanting to know your odds of receiving hurricane force or tropical storm force winds, I recommend the NHC wind probability product.

Wunderground has detailed storm surge maps for the U.S. coast.

Elsewhere in the tropics
A tropical wave far out in the eastern Atlantic about 200 miles southwest of the Cape Verde Islands, Invest 90L, is showing signs of organization. NHC is giving this disturbance a 50% chance of developing into a tropical depression by Friday. Several of our models do develop 90L into a tropical storm by early next week, but long-range models are showing that this system will not be a threat to any land areas over the next seven days, and will probably move too far north to ever be a threat to land.

Internet radio show on Irene at 4:30pm EDT today
I'll be discussing Hurricane Irene on a special edition of our Internet radio show, the Daily Downpour, today (Wednesday) at 4:30pm EDT. Fellow wunderground meteorologists Shaun Tanner, Tim Roche, and Angela Fritz will also be there. Listeners can email in or call in questions. The email address to ask questions is broadcast@wunderground.com.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 190 - 140

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30Blog Index

Quoting rkay1:
FLORIDIANS! What is with you people? Do you have some kind of weird fetish with Hurricanes? The storm is RIGHT on track.  There is not 1 model pointing remotely to FL --Actually most of the models barely having it hit SC anymore, let alone FL.  Let it go, its just annoying now. "OMG DID IT JUST WOBBLE WEST? WHAT DOES THIS MEAN FOR FL?!!"


I don't think it's all "wish-casting" as some here refer but rather watching the storms very closely until one is sure the storm has passed them. It's a pain to prepare for a storm, and the aftermath is even worse so it behooves a Floridian to keep a close eye on the topics during the season.

I'm not on the edge of my seat for every wobble but if model runs and/or satellite observations start trending my way, I take notice.



Member Since: Posts: Comments:
Quoting WeafhermanNimmy:


I am so hoping this moves into Charleston, SC. So we can get some good impacts in Greensboro, NC. Hoping praying to god! We need the rain!


I'm certainly NOT hoping for that ... this thing is a whole lot more than rain! I hope for it to miss everyone!
Member Since: Posts: Comments:
187. DVG
I was wondering about a couple things. First does the low east of Ga have to be demolished for the predicted effect of the troughs to take place?

Second, watching the eastern US infrared 2 loop, I see something and was wondering as to whether it's related to the bermuda high. At about 72 long and 37 lat extending to 55 long, there is a dark, I don't know what to call it except is it an air mass?

So is this dark area moving north part of the blocking atlantic ridge?

Member Since: Posts: Comments:
Quoting alvarig1263:


No one, I hope. I'm just saying, he's berating people so much about THEIR opinions about it coming close to FL, so much as if he's gonna loose a bet or something if it hits FL. lol
.

YOU have agreed with several posts predicting a Florida landfall. Please post that you were wrong AFTER is doesn't. Okay?
Member Since: September 4, 2009 Posts: 0 Comments: 158
Quoting marknmelb:


You mean the point where it was supposed to go further up the coast then took a sharp left hand "bump" ???


Andrew was no surprise...we new days in advance he was coming.




Now the strength is another story. That sucker went from a 1 to a 4 overnight.
Member Since: August 4, 2011 Posts: 0 Comments: 292
Quoting WaterWitch11:
my first poof. i'm so excited. now back to the weather.


lol
Member Since: Posts: Comments:
182. wpb
next group of waves off africa 90l etc will be pull north out to see. ridging forecast be weak out there for the next ten days at least.
Member Since: Posts: Comments:
saw a coast guard c130 3 times in a hr here in sarasota,are they part of recon??
Member Since: October 5, 2007 Posts: 20 Comments: 4970
179. CAAM
It is so strange to be calmly going about my business here in South Florida with such a strong storm in the neighborhood.

Science and technology have sure come a long way. And, I guess, our confidence in them as well. :-)
Member Since: Posts: Comments:
my first poof. i'm so excited. now back to the weather.
Member Since: Posts: Comments:
Quoting Thrawst:
Weather here is still decent. Winds are slowly rising though.


Which island are you on again?
Member Since: December 18, 2006 Posts: 7 Comments: 2687
Quoting rkay1:
FLORIDIANS! What is with you people? Do you have some kind of weird fetish with Hurricanes? The storm is RIGHT on track.  There is not 1 model pointing remotely to FL --Actually most of the models barely having it hit SC anymore, let alone FL.  Let it go, its just annoying now. "OMG DID IT JUST WOBBLE WEST? WHAT DOES THIS MEAN FOR FL?!!"


Your hilarious! lol ;-)

I love these blogs...
Member Since: Posts: Comments:
For two and half hours, Irene has headed in a straight dead wwnw to wnw heading, at about 11 miles an hour. so she has traversed about 30 miles

while this may be a temporary jog...it has certainly not wobbled a bit. heading on a straight line.

if it kicks north...ignore this. if it continues...

pucker up Florida.

I am NOT BUYING the models. It will trend more west.

Florida is NOT out of the woods..

imho...

and neither is the GOM.

the trough lifted out...the high is kicking further west (bermuda)
Member Since: Posts: Comments:
Blog update...Irene responseLink
Member Since: Posts: Comments:
Quoting FLdewey:


You HAD a flight out of JFK. ;-)

No seriously - travel in the NE is going to be a nightmare. EWR should be a total zoo. (More than normal)
Can't imagine evac. for 30 million people!
Member Since: Posts: Comments:
Quoting TruthCommish:


Who does?


No one, I hope. I'm just saying, he's berating people so much about THEIR opinions about it coming close to FL, so much as if he's gonna loose a bet or something if it hits FL. lol
Member Since: Posts: Comments:
Does anyone have a overlay map that shows the NHC track and actual live radar?
Member Since: Posts: Comments:
so... sneaking in again..I have seen THE STORM WILL NOT PASS 77 WEST.

So if the storm DOES pass that point what would it mean for Fl?

And if it means anything, is it just So FL?

thanks!

Member Since: Posts: Comments:
For people focusing on the Cone -- remember the cone indicates ONLY where the eye may be. The actual area of hurricane and TS-force winds can extend hundreds of miles beyond the eye-cone. Irene is a HUGE storm, so even if her eye remains offshore, populated areas may still fall well within threat range.
Member Since: Posts: Comments:
Weather here is still decent. Winds are slowly rising though.
Member Since: Posts: Comments:
Until that Tough, that will kick Irene to the east moves over land (currently over the Northern Pacific) and gets some real sampling for the models to chew on, I’m not looking at one more model run, or new track.

That should occur by the 12Z runs on Thursday. Anyone that follows North East storm prediction must always use caution until the key players move off of the Pacific and onto land (where there is much improved actual sampling in place, then a few sporadic buoys bobbling up and down in that part of the ocean). Those factors usually do not play into any hurricanes crashing into FL, or the Golf coast.

Thursday's 12z Model output is where the fun begins, or ends.
Member Since: Posts: Comments:
Quoting marknmelb:
Ok based on the 1100Am update and a 956 MB storm here are the wind fields

Previous



And current



I am so hoping this moves into Charleston, SC. So we can get some good impacts in Greensboro, NC. Hoping praying to god! We need the rain!
Member Since: Posts: Comments:
Quoting Grandpato4:
Our local weather folks seem to think we won't get more than a few gusty winds with the current forecast track. I am not letting my guard down, but I feel a bit silly sitting in a house with hurricane shutters up right now.
Consider it a "shake down" cruise. This is where you find out what you need to do to put on the shutters. It is more common than uncommon for there to be some difficulty that needs to be ironed out. Next time you will have your procedure set.
Member Since: Posts: Comments:
Bluestorm I live in Fayetteville, NC what kind of winds can we expect here? did thet mention track shifting cuz WRAL news said models trending more east.
Member Since: Posts: Comments:
160. maeko
Quoting tiggeriffic:


and i DID NOT LISTEN TO THEM...i was laughed at when buying stuff...told i was nuts...then the same people knocked on my door wanting what i had cuz they were not prepared...go figure...by no means am i saying we are gonna take a direct hit from Irene...don't get me wrong...but i am saying models can be wrong and you should ALWAYS be ready


yes, and this gives me pause. i have plans to leave Chas on Thurs night(ironically, for DC and seemingly greater threat). i am gearing up to go ahead with my plans. however, because of duties, i am required to be back in Chas within 24hrs if there is significant damage. Irene is giving me headaches as to secondary plans for return! any thoughts about worst case scenerios for Chas (beside total change to direct hit)?
Member Since: Posts: Comments:
Quoting alvarig1263:


You really do not want Irene hitting FL don't you?


Who does?
Member Since: September 4, 2009 Posts: 0 Comments: 158
Quoting tj175:
To my fellow South Floridians, Happy 19th Anniversary of Hurricane Andrew. I was 8 years old on August 24, 1992 and I still remember the point up until the storm and the aftermath.


You mean the point where it was supposed to go further up the coast then took a sharp left hand "bump" ???
Member Since: July 17, 2006 Posts: 0 Comments: 408
They actually do a great job of forecasting here is Florida.  Every day they state.  Hot and humid. Possible showers in the morning followed by afternoon Thunderstorms.  30% chance of rain overnight.....repeat...repeat...
In SEP they start off each broadcast with "monitor Tropical Storm/Hurricane watch for updates. Not as hot.
This then gets changed slightly in OCT/NOV. 10% chance of rain.

Quoting SCwannabe:



They can barely forecast if were going to get thunderstorms on any given day


Member Since: Posts: Comments:
Quoting KEEPEROFTHEGATE:


the storm WILL NOT PASS 77 WEST
fla is safe minus some costal surf breezy conditions
and i don't forecast i track


Keeper that's a pretty bold prediction when she's already crossed 74W and is still heading WNW! I'm not saying she will but I won't say she won't either, the forecast track takes her pretty close to 77W before she's supposed to turn NE! Time will tell!
Member Since: Posts: Comments:
Quoting rkay1:
Is this guy for real? Really? Denial is scary!



You REALLY do not want Irene hitting FL....
Member Since: Posts: Comments:
So the eyewall gap is a small one on the SW side? i seein correctly? dont think it will take day to complete like last time, much stronger now
Member Since: August 4, 2011 Posts: 46 Comments: 4488
152. NJ2S
Quoting Speeky:
Who thinks that Irene could make a direct hit on NYC?


I hope not I have a flight out of JFK on saturday
Member Since: Posts: Comments:
150. tj175
To my fellow South Floridians, Happy 19th Anniversary of Hurricane Andrew. I was 8 years old on August 24, 1992 and I still remember the point up until the storm and the aftermath.
Member Since: Posts: Comments:
147. 7544
another good jog west hmmm
Member Since: Posts: Comments:
Quoting hurricanejunky:
Anyone care to chime in on the disaster potential associated with the number of nuke plants on the Eastern Seaboard?
I live 15 miles from a nuke plant here is st lucie , fl and it has gone through 3 intense hurricanes so I think the others should be alright.
Member Since: Posts: Comments:
Quoting FLWaterFront:
Exactly. But those who keep insisting that Irene is sure to hit Florida because they are seeing it move in a WNW direction at this very moment are not paying any attention to the advances in tropical weather forecasting that have taken place over the past 22 years.

I wonder how many people would ignore the advances that have taken place in electronic communications over the past 22 years? Did anybody here have an iPhone back in 1989? How about a tablet or a plasma TV? What were those like in '89? Or if you are too young and were not yet born then, ask your parents.


And like Levi said in his video, the models really haven't done all that bad. When Irene's center was relocated just north of Puerto Rico, most of the models were clustered towards SC and much of the SE, now it has shifted to the OBX. That's pretty good 7 days out on a global model. Plus, the current models that we are looking at have the G-IV data incorporated into it vs. last week when we didn't.
Member Since: Posts: Comments:
Quoting WaterWitch11:


how about solar flares and earthquakes, do they have a connection?


Poof.
Member Since: Posts: Comments:
141. Gorty
Interesting!

Link

60 mph gusts with 4-8 inches of rain for me in the Springfield Mass area! Assuming it goes their path.
Member Since: Posts: Comments:
Quoting tiggeriffic:


actually, if that were true, there would not be a "CONE"...not saying forecasting is easy, but no one can predict with unequivicable accuracy...they watch what is to each direction, what way is it moving and what NORMALLY would happen and forecast on that information...sometimes it is right, sometimes not... that is why they have percentages...


Why wouldn't there be a cone? I didn't say the forecasts were perfect. Just saying that predicting where small t'storms will or won't pop up is much harder than predicting the movement of large-scale features.
Member Since: Posts: Comments:

Viewing: 190 - 140

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Local Weather

Overcast
34 °F
Overcast